


On an Incidental Tide

by ellipsometry



Series: fishvain au [1]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: (mild blood kink...), Alternate Universe, Blood Kink, Double Penetration, M/M, MerMay, Overstimulation, Shark Sylvain, Size Kink, Trans Felix Hugo Fraldarius, Wet & Messy, sylvain is a bigass shark and has two dicks that's the entire premise
Language: English
Status: Completed
Published: 2020-05-28
Updated: 2020-05-28
Packaged: 2021-03-03 00:26:36
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,949
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24425740
Author URL: https://archiveofourown.org/users/ellipsometry/pseuds/ellipsometry
Summary: “Stop looking at me like that,” Felix says, in a way that Sylvain knows to meannever ever stop looking at me like that.“Like what?”“Like—” Felix’s voice hitches, the flat of his palm hitting his dick, a jolt of electricity that he chases with his fingers, crooking them up, apart, groaning as he stretches his hole wide. “L-Like you’re going to eat me.”Sylvain, never a subtle being, licks his lips, eyes wide with want.  “I might.”It's finally summer; time for Sylvain to make good on an old promise.
Relationships: Felix Hugo Fraldarius/Sylvain Jose Gautier
Series: fishvain au [1]
Series URL: https://archiveofourown.org/series/1994251
Comments: 14
Kudos: 368





	On an Incidental Tide

**Author's Note:**

> gggggggggggggggggggggggggggggggggg  
> thank u casey for [sharkvain brainworms](https://twitter.com/eggyankee/status/1258850886136336386?s=20) i owe u my life
> 
> heads up both amab/afab terms used for felix's junk

There are benefits, Felix learns, to having a family-owned private beach.

Today they’re exploring the west side of the property, the shoreline untouched and overgrown with knee-high saltbush. _I want you to decide what to do with it,_ Rodrigue tells Felix. And maybe this isn’t exactly what his father had in mind, Felix thinks, as he curls into the lap of his massive, half-shark boyfriend.

“You’re impatient today,” Sylvain mumbles, but the grit in his voice and the too-hard press of his fingers around Felix’s hip tell Felix that he’s feeling it too. It’s been weeks since they’ve had time alone together, responsibilities and finals and family obligations keeping Felix away from the beach.

But summer is finally here. And it’s time for Sylvain to make good on an old promise.

To call Sylvain _large_ would be an understatement. There’s really no other way to say it – when Felix first encounters him, caught too-deep in the undertow, he thinks the flash of blood red scales and tan skin must be a hallucination before death finally takes him. Nothing else could explain a half-man, half-shark gliding toward him, grinning in an uncanny human-like way, but grasping one inhumanly large hand around Felix’s middle to hoist him to the surface. Felix prods at the small bruises on the sensitive slope of his waist for weeks, and waits every day at the docks for whoever or whatever that was to return.

 _I thought I scared you off_ , Felix says, when Sylvain finally shows his face after a week of hiding, eyes popping up above the waterline. And Sylvain laughs so loud the seawater around him reverberates with it, gleeful and straightforward, because _why would I ever be scared of a human?_

But maybe Felix was a little right, Sylvain thinks. Because if he’s scared of anything, it’s how much he wants Felix, how much he craves him, wants to take him apart and put him back together again.

“Shut up. I missed you,” Felix mutters, red face buried in the swell of Sylvain’s chest. “Is that not allowed?”

 _Goddess he’s so fucking cute_. “Of course it is, kitten.” He kisses the top of Felix’s head, a deceptively chaste action, considering how they’re both hard and dripping, sticky with sweat and already breathless with anticipation. Sylvain runs a hand down Felix’s back, the span of it as wide as his waist. 

Felix has never liked it – feeling small. But around Sylvain, it doesn’t feel that way. He just feels safe.

“Then—” Felix whines, petulant, lifting himself up just enough to kiss at the jut of Sylvain’s jaw. It’s been a fight to even get this far – a fight with Sylvain, too afraid to hurt him. A fight with himself, scared to be vulnerable like this.

But Felix grinds his swollen dick against the ridges of one of Sylvain’s cocks, the rough drag of it making him dizzy with want and – _yeah_ , it’s fucking worth it.

“Baby, you’re—” Sylvain huffs out a laugh. “Let me, okay?”

Felix nods furiously, eyes clamped shut. It’s easy to let Sylvain take control, to let him grip Felix’s hips, pull apart his legs, perch Felix between his two cocks, a perfect throne; one cock grinding dirty against Felix’s clit, the other curving around his ass, hitting at the shallow dimples in his back, slick precome dripping down his crack.

“Syl _vain_ ,” Felix’s voice cracks on the second syllable and _god_ he’s already too keyed up, too desperate from so many nights away from Sylvain, hours spent pressing fingers inside himself, too clumsy and riled up to replicate this feeling of Sylvain around him.

“I got you,” Sylvain’s voice is soft in his ear even as his grip tightens around Felix’s waist, manhandling him into place, grinding him up and down easily, enjoying the slick drag of his cocks against this tiny human, soaking in the messy noises that have Felix going red with embarrassment and thrill and—“Come for me, come on. You’re twitching so hard, know you want to.”

“D-Don’t, _fuck_ ,” Felix bites down at Sylvain’s collar bone, a pathetic, tiny pink spot against the broad span of his chest. And as one ridge of Sylvain’s cock catches against his clit, he shakes apart, gushing onto Sylvain’s lap, wet like a tap that’s just been opened. Sylvain’s hand strokes down his back, claws scratching tiny ridges of pink that leave Felix’ shivering as he comes down from his orgasm, mind slowly floating together again.

Against him, Sylvain is still hard. Good. That means—” O-Okay. F— _hah, fuck_ —you can fuck me now.”

“Baby—”

They’ve done this before, of course, with Felix spread wide around one of Sylvain’s cocks, almost sobbing with the feeling of it, full and claimed. And after not being able to be alone together for so long, Felix is far from the only one feeling desperate. It’s easy to feel how much Sylvain wants him, the press of his claws against soft skin, the way his tail curls in the water, splashing salt across Felix’s legs.

Still, it’s like the air is punched out of him when Felix slides a hand up Sylvain’s chest and says, “Both of them.”

“ _Fuck—_ Felix—” Sylvain chokes on the air, webbed claws pressing so hard into Felix he almost draws blood. Beneath Felix, his cocks twitch traitorously, leaking thick slick onto Felix’s thighs. Felix grins like a cat who’s just got the cream. Finally, after all these months, all the waiting and trepidation, and—

“We are… not doing that.”

A pause. “Excuse me?”

“Baby,” Sylvain looks pained, even as his cocks press insistently against Felix’s ass. “You can hardly take _one_. I may be… you know, but I don’t want to kill you.”

Felix folds his arms over his chest. This would look more forceful if he wasn’t literally perched in between two shark dicks. “But you said last time—”

“I was—” Sylvain makes an incredulous noise, voice lowering to a hiss. “It was just dirty talk!”

“Since when do mermaids dirty talk?”

“Since fucking—you should know!” Sylvain crosses his arms too, pouting like a scolded child. “And I’m not a _mermaid_ , we’ve been over this.”

“Look,” Felix wraps a small hand around one of Sylvain’s cocks, still hard, and twists his wrist mean, earning a punctuated groan out of Sylvain. “You know I don’t say shit I don’t mean. And I know you want it too. I trust you.”

Sylvain’s mouth drops open as Felix strokes down his dick, squeezing hard around the tapered head. But his words alone are enough to have Sylvain groaning, the way Felix seems to ready to hand himself over fully, no questions asked. “Y-Yeah?”

“Yes,” Felix smirks, pushing his ass back against Sylvain’s second cock. “We can wait, but I _trust_ you, no matter what. Get it through your thick fucking skull. Besides…”

Sylvain watches, slack-jawed, as Felix props himself up, sitting on the head of Sylvain’s cock, letting his hole mouth eagerly at the tapered head before sinking down, the slow, steady burn of it making them both exhale hard.

“We have the whole summer ahead of us.”

+

Falling in love with Sylvain is an accident. 

It’s an inconvenience, honestly. Sylvain is a fucking _deep-sea creature_ , a familiar human torso that grades into a wholly unfamiliar, inhuman tail, red-orange like a sunset, a strip of white running down his flank. He’s at least nine feet long, maybe longer, enormous in the way megafauna use to be millions of years ago, a time capsule of a creature that Felix tentatively opens and never figures out how to close. Never _wants_ to, really.

There are scars crisscrossing Sylvain’s body, some of them mottled, whited over and decades old, some fresh enough that Felix frowns running his fingers over them. 

Felix can’t protect him. So, he loves him instead. Fiercely, with all the fire in his being. What else is there to do?

“That’s embarrassing,” Sylvain teases him, a bit of deflection that Felix learns to tolerate. “You have a crush on a shark.”

“I don’t have a _crush_ ,” Felix grumbles. “Isn’t it more embarrassing for a huge ass, ancient sea creature to fall in love with a human? Your mermaid friends will make fun of you.”

Sometimes, Sylvain goes quiet, serious. It’s one of those times, and he rubs a thumb across Felix’s cheek, cradling his head in his palm. “Not at all. If they saw you, they’d fall in love too.”

Felix lets himself believe it. He’s never felt as desirable as he does under Sylvain’s gaze, held tight against his chest, or under the water with Sylvain gripping him tight. Back on land, Felix a scrawny, scowling nuisance to most people. The way Sylvain looks at him – like he hung the moon and all the stars – is sometimes too much to believe.

“Then there’s something wrong with them,” Felix mumbles, hiding his face from Sylvain, hiding the way it splits into a grin. “And with you.”

+

Felix wants to hate this part.

It takes a bit to wear Sylvain down – or, rather, for Felix to convince him that he really, truly trusts him, that he wants _all_ of him, wants to be his. And Sylvain, as flaky and strange and insatiable as he can be, sets about preparing a comfortable place for Felix like it’s what he was born to do. He settles on a small grotto at the edge of the Fraldarius property, and he carries Felix there on his back; Felix runs his hand through the clear-blue water as they go, and tries to catch his breath.

“It’s not too—and you know the water here is where fresh water meets sea water, so maybe it will be less irritating on your skin.” Sylvain grins wide, teeth glinting in the high afternoon light. And as sweet as he’s being, all Felix can think is how easy Sylvain could tear him apart. How easily he could, and how he never will.

So, Felix wants to hate this – the preparation. The way Sylvain fawns over him, watches him with eager, searching eyes. But, as he shucks off his board shorts, revealing the tiny, string bikini bottoms underneath, Felix can’t bring himself to hate this. The anticipation is almost as good as the real thing, sometimes.

“Fe…”

“Shut up now, please.”

Felix spreads out on one of the low rocks, lukewarm from the sun. Sylvain swims over, propping his arms at the base of the rock, face peeking out between Felix’s ankles as he spreads his legs, heels digging into Sylvain’s shoulders.

Sylvain reaches up to wrap one hand around Felix’s ankle, and his fingers span it easily. “Felix,” he repeats, low and dangerous, watching as Felix unties the side of his bikini, strings laying haphazard and tangled against pale skin. Beneath it he’s wet, dripping onto the damp rock below. He runs a hand across his mound, tweaking his dick, and exhales hard.

“Baby, did you—”

“It takes too long,” Felix mumbles, half-whining at how turned on he already is, the promise of being split open making him dizzy with want. There’s lube dripping out from his hole along with his arousal. He’s already messy with it and they haven’t even begun. “I prepared myself back at the house.”

Sylvain’s mouth goes dry. They both know how long it takes to stretch Felix out, and Sylvain’s webbed, clawed fingers aren’t exactly the best thing for the job. Still, the sheen of Felix’s arousal is enough to have Sylvain’s cocks peeking out from his slit already. He’s so gone already, so sensitive as he slides fingers inside himself, a wet slap as he grinds against them.

“Stop looking at me like that,” Felix says, in a way that Sylvain knows to mean _never ever stop looking at me like that._

“Like what?”

“Like—” Felix’s voice hitches, the flat of his palm hitting his dick, a jolt of electricity that he chases with his fingers, crooking them up, apart, groaning as he stretches his hole wide. “L-Like you’re going to eat me.”

Sylvain, never a subtle being, licks his lips, eyes wide with want. “I might.”

Felix is panting now, fingering himself furiously, watching Sylvain watch him and feeling the heat of his gaze burn his skin like a brand. “M-Make up your mind then.”

Luckily, Sylvain has never been one for indecision.

He throws Felix’s legs over his shoulders, propping his torso up on the rock so he can plant his face firmly against Felix’s cunt, eager tongue lapping at the curve of his lips, dipping in lightly to tease his hole, tasting the salt and musk there. Every minute movement and flick of his tongue has Felix shivering apart under him, so close to coming already.

“You can come,” Sylvain’s voice is a rumble against Felix’s clit. “I won’t stop.”

He can hear Felix swallow, can feel him slip under, surrender himself to the sensation, orgasm coming on so slowly that Sylvain might have missed it if Felix wasn’t literally dripping into his mouth. Around Sylvain’s head, Felix’s legs shake, hips bucking up desperately into Sylvain’s mouth. He gasps wetly when he feels Sylvain’s tongue flick at his clit, oversensitive and swollen.

Sylvain doesn’t intend to stop. He promised, after all.

Sharks lose teeth and grow replacements all the time. Sylvain learns to rely on that, as different humans over the years catch him and pull his teeth out as trophies, or file them down, experimenting with him. As the years wear on, some of his teeth grow in a bit wrong, dulled, less lethal. Humans are omnivores, after all, and Sylvain is still half-human. Now, as he opens his jaw wide, pulling Felix into the seat of his mouth, Sylvain wonders if that’s a blessing after all.

The dulled edges of his teeth scrape just above Felix’s mound, on the inside of his thighs, leaving small red indents in the soft flesh. Felix is boneless and blissed out from his first orgasm, but still squirms under the pinpricks of pain. He likes the pain – Sylvain knows this from experience, but also from the way Felix’s dick twitches eagerly under his mouth. Sylvain wraps his tongue around it and sucks, _hard_.

“S-Syl— _fuck, Sylvain—”_ Felix half-screams, back arching taut, legs attempting to clamp shut, accidentally scraping Sylvain’s teeth further against the sensitive flesh of his inner thighs. “Please, fuck, please—” He’s babbling, and Sylvain is already drunk on the taste of him, lapping at him eagerly, up from his hole to his swollen dick, flicking at it harshly.

Sylvain’s tongue, at its base, is as wide as a normal human’s dick. That alone makes it perfect for preparing Felix, and his dips it in slowly, curling softly at until he finds Felix’s g-spot, until Felix is keening and crying for more. He grinds against Sylvain’s mouth, riding his tongue as it inches in deeper, curling against sensitive, tight walls.

“Sylvain,” Felix sobs, grasping for anything near him, reaching down to tangle his hands in the mess of Sylvain’s hair, damp from the warm sea water. He can feel the slight curve of Sylvain’s smirk, the way his tongue digs deeper and _deeper_ and – _fuck, goddess just like that, yes –_ one well-placed stroke of Sylvain’s tongue and Felix comes undone again, vision whiting out as his back goes taut, arched up from the warm rock below.

“Hmm,” Sylvain just hums beneath him. And, menace that he is, scraps his teeth every-so-lightly against Felix’s overstimulated clit.

Felix wails, voice echoing around the low walls of the grotto, trying to pull himself away but finding his limbs too weak to cooperate. Sylvain growls a possessive, warning noise, and an instinctive shiver runs down Felix’s spine. He goes down easy, covering his face in his hands as he whimpers. Sylvain works him over, licking up every drip of wetness from Felix’s hole, circling his clit until he’s swollen and red. And, when Felix thinks he can’t take any more, another orgasm hits him, slow like molasses, a syrupy warmth that spreads from his toes to the tip of his ahead. Dark spots dance in his vision, and Felix gulps in the humid, salty air.

When he comes back to himself, Sylvain is still there, between his legs, kissing the small red cuts on his legs apologetically. He gives Felix a conspiratorial wink, lifting up his thighs, until he can see a small, silver glint winking at him from between Felix’s ass.

“Were you gonna tell me about this little guy?” Sylvain grins, finger tapping at the head of the plug in Felix’s ass.

“J-Just—give me a minute, okay,” Felix pants, eyes clamping shut as the plug moves inside him. It’s the biggest one he has, and still nothing compared to Sylvain’s cocks. Maybe that’s why everything feels so intense, every movement of Sylvain’s tongue against his body causing him to clench down around the plug spreading him wide. “Didn’t I s-say I prepared myself?”

“You’re filthy,” Sylvain hikes Felix’s legs up further, until his lower back is arched off the rock, Sylvain breathing hot and heady against his ass. “You want me to fuck you that badly?”

“Yes, fuck, _yes,_ ” the answer tumbles out before Felix can think twice.

He’s so good like this, pliant and sweet under Sylvain’s hands. And so easy to move, to toy with like Sylvain’s personal plaything. It’s nothing for Sylvain to grip Felix’s waist, one hand reaching all the way around, pulling him down onto his lap.

“You feel them?” Sylvain breaths into Felix’s ear, relishing the way he shivers against him despite the heat. His cocks slap against Felix’s ass, hot and wet. “They want to be inside you so bad, want to stretch you out until you’re ruined for anyone else.”

“My—I want it, Syl—” Felix curls his fists against Sylvain’s chest. “Wanna be yours.”

 _You’re already mine_ , Sylvain wants to say. Felix has been his since he first set eyes on him. And still, Sylvain aches to be inside him, to carve out a space no one else can ever touch, to _mark_ him, inside and out.

“You are,” Sylvain paws at Felix’s ass, pulling his cheeks apart until the plug is exposed, tapping at it experimentally, just to feel Felix squirm. It’s clumsy, trying to pull it out, Sylvain’s hands almost too large to get purchase around it. Finally, he succeeds – and pulls it out achingly slow, watching over Felix’s shoulder the way his hole stretches around the large curve of it, the way it gapes when the plug finally drops out, lost to the shallow ocean water below.

(Sylvain will figure out way to get him a new one later.)

“So empty without me.” Sylvain says curiously, pulling and squeezing Felix’s ass. He’s never fucked Felix here before, but the way the clutch of his asshole winks at him, pink and wet and inviting – something in the space of Sylvain’s chest grows hot with want. The pad of his finger catches against Felix’s rim, and he teases at it lightly there. He can’t finger him but he can—

“W-What are you doing— _fuck, shit_ —” Felix’s back arches, and pressing his chest against Sylvain’s as something dips into his ass, stretching him just as much as the plug. It takes him a second to realize it’s Sylvain’s finger, folded up, his knuckle pressing inside. The strange shape of it makes Felix moan, loud enough that it startles him.

Sylvain makes a satisfied noise, the soft frills on the side of his face going pink. “I’ve wanted you for so long. You have no idea.”

 _Of course I have an idea_ , Felix wants to say, wants to make a quip about Sylvain’s obviously-hard cocks, and his obvious flirting, and his obvious, unvarnished smile. But there’s an edge of Sylvain’s voice that stops him, and the feeling of his dick pressing inside his front hole has Felix’s mind going blank. “ _Shit—_ ”

They go quiet as Sylvain lowers him down, each ridge catching against his clit before sinking inside, a familiar but delicious stretch; Felix panting, chest heaving under the effort to keep himself still, rather than fuck down on Sylvain like he wants to.

“So tight…” Sylvain breaths in, voice shuddering already. “So perfect for me.”

“Syl,” Felix’s head lolls back as Sylvain bottoms out inside him, grinding slow against the curve that presses perfectly against his g-spot, savoring the feeling of being _full_ for the first time in weeks. “Fuck, you—"

“Sorry, can’t—” Sylvain grits his teeth, and Felix feels a gush of slick inside him, trapped inside by the seal of Sylvain’s cock inside him. He’s never come so fast inside Felix before. “Goddess, fuck—Fe, you’re so full of it.”

He guides Felix’s hand to his stomach, the obvious bulge of Sylvain’s cock, an obscene bump, proof of just how much larger Sylvain is; proof of how _deep_ he is, deeper than anyone else could ever get. Proof that Felix is _his_.

“Y-Your—you came inside,” Felix is already babbling, drunk on the feeling, bucking his hips up to see the bulge move, pressing on the head of it, stroking Sylvain’s cock through his own stomach. “M-More— _hahh—_ Syl, give me more, I want it I want it—”

“Fe…” Sylvain’s voice is a warning, low and quiet. Something is unraveling inside him quickly, and maybe it’s the fact that he hasn’t been inside Felix in what feels like forever; or the swell of his stomach, only growing larger as Sylvain’s seed pours inside him; or the way Felix’s hair lays wet against his shoulders, falling in his face as he breaths in, shuddering breath after shuddering breath. Sylvain’s pupils go thin, the fins on the side of his face flaring.

“Mine,” he growls, low from the depth of his chest, bucking his fin up, rocking his cock inside Felix, the other catching at the swollen rim of his ass, the dirty promise of it making them both groan.

“I-Inside,” Felix gasps, mouth wet with saliva and the taste of salt. “I don’t – _uhn_ – don’t wanna feel anything but you.”

That’s an easy promise for Sylvain to keep. He pulls Felix’s thighs up, letting him slump against his chest, and Felix goes down easy, lets Sylvain move him like he’s his personal cocksleeve – and he might as well be, like this, whimpering as Sylvain’s second cock slowly carves into his ass, inch by aching inch. Sylvain runs a hand down his back, Felix shaking apart with every second, sobbing at how overwhelming it is, pain and pleasure mingling. And Sylvain is only half-deep in his ass when Felix clenches tight, milking him so hard it almost hurts – and there’s a flush of liquid against Sylvain’s lap.

“You…”

“S-Shut up,” Felix slurs, eyes rolling back into his head. It’s not the first time he’s squirted, but the first time it’s been so intense. He presses down on the growing bulge in his stomach and cries out, shuddering through the aftershocks, chasing the small orgasms that rock through him, dripping obscenely around Sylvain’s cocks, easing the glide of them as Sylvain bucks up.

“ _Fuck_ , that’s sexy,” Sylvain laughs but there’s an edge to his voice, a grit that tells Felix he’s hardly holding back. “You’re so full of me, fucking ruined for anyone else.”

“Th-There isn’t—"

“I know, baby, I know.” Another inch sinks into Felix’s ass, and Sylvain hikes him up so he can properly bounce Felix in his lap. “No one but me, I know. You’re too much of a cock slut for anyone else to satisfy you, right?”

 _Fuck_ , it’s true. Felix’s eyes are hot with tears and it’s _so true_. Nothing else could compare to this, to the feeling of being owned so completely, split apart, two cocks sawing through his guts as Sylvain holds him effortlessly with those massive claws, moving him up and down his cocks mercilessly. He can’t feel anything, _think_ of anything else, Sylvain so deep in him Felix swears he can taste it.

“More— _hic—_ more, _please_.”

“Anything for you, sweetheart.” Sylvain bites down hard at the soft curve of Felix’s neck, hard enough to draw blood, to watch the red slip down his collarbone, down his chest, catching on the hard nub of his nipple. The scent of it itches at some ancient, deep scratch inside him – the first Felix had bled in front of him, Sylvain had nearly killed him, ripping open his clothes, bending him over the dock outside Felix’s home. 

Now, he’s learned restraint, enough to cradle Felix’s shoulder in his mouth, deceptively gentle, biting down in time with his thrusts, tongue curling over the small cuts, lapping at the fresh blood. _My own personal meal._

“Syl—Syl, please—” Felix is lost in the pain and the indulgence of it, dick overstimulated and sore from rubbing against the gradient of Sylvain’s scales, a fine-grit sandpaper burn that brings him to the knife’s edge of pleasure and back again. Salt tracks down his cheeks, dripping onto Sylvain’s chest, mingling with Felix’s blood, the sweat, a wet mess that Felix falls into, limp and pliant and just there for Sylvain to use.

“You love this,” Sylvain growls against Felix’s neck. “ _Goddess, fuck_ , I should have fucked you like this earlier. You need it so bad, need to be completely full.” He can feel Felix nodding furiously against him, crying out nonsense, just a litany of _yes_ and _fuck_ and _Sylvain, Sylvain, Sylvain._

Something snaps inside of Sylvain, something base and ancient, an old instinct kept buried. The snap of his cocks inside Felix grow harder, meaner, punching small, wet noises from Felix’s mouth. “I’m close, baby. You want me to fill you up proper, right?” His voice is hoarse, like the sound of a match strike in Felix’s ear. “You’ll be dripping me for weeks, kitten. Everyone will know you’re mine, that you let me fuck you full until you couldn’t take anymore.”

Felix wails, shuddering through another orgasm as Sylvain bucks into him, _hard_ , and holds himself there, both cocks painting Felix’s insides, pumping his seed inside until Felix swears he can see the bulge of his stomach grow, can taste it in his mouth. Sylvain howls, a loud whistle as his gills open, eyes going dark. He holds himself there for what feels like hours, and Felix is squirming around him, savoring the splash of hot come inside him.

Finally, Sylvain’s cocks go soft.. He pulls out of Felix slowly, carefully, an obscene wet squelch as come drips out of both his holes. “Goddess, fuck sweetheart. You really are full up with me.”

“Mmn—” Felix is shaking under Sylvain’s touch. He traces his claws carefully around Felix’s body, rubbing at the gaping rim of his ass, that once-tight clutch pulled wide; teases his wet lips, sore clit, watching the come drip out slowly. Sylvain wants to fuck all his come back into Felix, until he’s swollen with it, until he’s drunk on it, half-unconscious, completely obedient. Completely Sylvain’s.

Maybe another time.

“’Vain… too much,” Felix whimpers, nudging his head against Sylvain’s chest like he could burrow inside if he tried hard enough. Sylvain acquiesces, stroking one last time against the sensitive flesh before pulling away.

“You were so good.” He kisses Felix’s forehead, then his cheek, the corner of his mouth, the cut of his jaw. “I love you so much. So, so much.”

“Y-You too,” Felix is blissed out, impatient to get clean and get some rest but… but he still likes this part. Likes Sylvain fawning over him. Even if he’ll pretend to hate it later. “Love you too. And thank you.”

“For what? Fucking you stupid?” Sylvain laughs.

“Shut up,” Felix swats weakly at Sylvain’s shoulder. “For keeping your promise.”

+

Falling in love with Felix is… well, not exactly an accident.

Sylvain almost can’t believe it when he sees him, that familiar shade of amber peering at him through the midnight blue water. He sees him, and he wants him. And it terrifies him.

“Do you think we’d be… you know. If you were a human?” Felix has asked this before, because he likes to hear the answer, something new and increasingly sappy, Sylvain weaving tales of all the different lives they might have lived. He likes the way Sylvain’s face goes soft, the way he curls down to capture Felix in a kiss, cradling him delicately in his hands. Like he’s something precious. Something worth having.

“If I were a human…” Sylvain hums. “I’d be insufferable.”

“You’re already insufferable.”

Sylvain barks out a laugh – or, rather, a kind of wheeze, his gills flapping. “More insufferable if I had a few hundred years less time to mature.”

Felix shrugs, settling down against Sylvain’s chest. He’s so sore already, but it’s a satisfying ache. Still, Sylvain will probably baby him for the next few weeks. And maybe, for once, Felix will let him.

“I think we’d still find each other. I wouldn’t be able to—” Felix pauses. How much of himself to lay bare? Is there even anything left hidden? He swallows. “I can’t imagine life without you.”

 _I can_ , Sylvain thinks. Of course he can – he spent hundreds of years without Felix, lost and fighting and doing anything but face that familiar shoreline, the pain that comes with loving a human you’re destined to outlive.

So, it doesn’t feel like an accident to have Felix here, falling asleep against him, summer-warm sea like a blanket around them. It feels like he’s exactly where he’s supposed to be.

Felix is already asleep. Sylvain kisses the top of his head anyway, and slowly, carefully, carries him back to shore.


End file.
